Well, this was an odd Thursday. It has a tricksy component, but the challenge is the extreme segmentation of the grid. Also, in case you hadn't noticed, the grid is asymmetric, with the two tetris segments of black squares placed differently and the southwestern border consisting of 2 squares as opposed to three in the northeastern border.
This is to allow for an extra set of SPLITPEAS at 11D/30D. The theme is phrases or words with double-Ps, which work as two independent words when you break them in between the Ps. Thus "whippets" becomes WHIP/PETS both of which work on their own. The best is definitely 28A: *Electrical current converter (POWERSUP/PLY). Nice to find that "powers up" in there!
I have noted before how little I enjoy grids where the flow of solving is dammed up by single letter connections between sections. In this grid, there are really five segments, all of which are connected to the other segments through single letter connections. So now I have complained, but it didn't really hurt my solve time too much (6:51).
Clues I enjoyed:
23A: Pronoun heard in "Hamlet" and "Richard II," appropriately (ROYALWE). Nice.
24D: Like the fact that Lance Bass sang bass for 'N Sync (APT). Apt!
43A: American charges (AIRFARES) - excellent hidden capital there.
47D: Flattened, in a way (IRONED). That's a very peculiar way to describe the act of ironing, but accurate.
Finally, the oddity of IINSIST must be mentioned. What a great way to account for adjacent Is. We approve.